High pressure valve with two-piece stator assembly

ABSTRACT

Valve with two-piece stator assembly for use with liquid chromatography or other analytical systems. A separate and removable stator plate is provided with a mounting device to provide a two-piece stator assembly. The mounting device is adapted on one side to engage and contact the stator plate, and on the other side includes a plurality of ports for fluidic connections which are in fluid communication with fluid passageways in the stator plate.

1. CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/373,584, filed on Dec. 9, 2016, which is hereby incorporated byreference in its entirety.

2. FIELD OF THE INVENTION

The present disclosure relates generally to valves such as those used inliquid chromatography systems and other analytical instrument systems.

3. BACKGROUND OF THE INVENTION

Liquid chromatography (LC) is a well-known technique for separating theconstituent elements in a given sample. In a conventional LC system, aliquid solvent (referred to as the “mobile phase”) is introduced from areservoir and is pumped through the LC system. The mobile phase exitsthe pump under pressure. The mobile phase then travels via tubing to asample injection valve. As the name suggests, the sample injection valveallows an operator to inject a sample into the LC system, where thesample will be carried along with the mobile phase.

In a conventional LC system, the sample and mobile phase pass throughone or more filters and often a guard column before coming to thecolumn. A typical column usually consists of a piece of steel tubingwhich has been packed with a “packing” material. The “packing” consistsof the particulate material “packed” inside the column. It usuallyconsists of silica- or polymer-based particles, which are oftenchemically bonded with a chemical functionality. The packing material isalso known as the stationary phase. One of the fundamental principles ofseparation is the mobile phase continuously passing through thestationary phase. When the sample is carried through the column (alongwith the mobile phase), the various components (solutes) in the samplemigrate through the packing within the column at different rates (i.e.,there is differential migration of the solutes). In other words, thevarious components in a sample will move through the column at differentrates. Because of the different rates of movement, the componentsgradually separate as they move through the column. Differentialmigration is affected by factors such as the composition of the mobilephase, the composition of the stationary phase (i.e., the material withwhich the column is “packed”), and the temperature at which theseparation takes place. Thus, such factors will influence the separationof the sample's various components.

Once the sample (with its components now separated) leaves the column,it flows with the mobile phase past a detector. The detector detects thepresence of specific molecules or compounds. Two general types ofdetectors are used in LC applications. One type measures a change insome overall physical property of the mobile phase and the sample (suchas their refractive index). The other type measures only some propertyof the sample (such as the absorption of ultraviolet radiation). Inessence, a typical detector in a LC system can measure and provide anoutput in terms of mass per unit of volume (such as grams permilliliter) or mass per unit of time (such as grams per second) of thesample's components. From such an output signal, a “chromatogram” can beprovided; the chromatogram can then be used by an operator to determinethe chemical components present in the sample.

In addition to the above components, a LC system will often includefilters, check valves, a guard column, or the like in order to preventcontamination of the sample or damage to the LC system. For example, aninlet solvent filter may be used to filter out particles from thesolvent (or mobile phase) before it reaches the pump. A guard column isoften placed before the analytical or preparative column; i.e., theprimary column. The purpose of such a guard column is to “guard” theprimary column by absorbing unwanted sample components that mightotherwise bind irreversibly to the analytical or preparative column.

In practice, various components in an LC system may be connected by anoperator to perform a given task. For example, an operator will selectan appropriate mobile phase and column, then connect a supply of theselected mobile phase and a selected column to the LC system beforeoperation. In order to be suitable for high performance liquidchromatography (HPLC) applications, each connection must be able towithstand the typical operating pressures of the HPLC system. If theconnection is too weak, it may leak. A leakage will definitely result inan unsuccessful or inaccurate analysis, such as inconsistent results ora total loss of the sample to be analyzed. Because the types of solventsthat are sometimes used as the mobile phase are often toxic and becauseit is often expensive to obtain and/or prepare many samples for use, anysuch connection failure is a serious concern.

It is fairly common for an operator to disconnect a column (or othercomponent) from a LC system and then connect a different column (orother component) in its place after one test has finished and before thenext begins. Given the importance of leak-proof connections, especiallyin HPLC applications, the operator must take time to be sure theconnection is sufficient. Replacing a column (or other component) mayoccur several times in a day. Moreover, the time involved indisconnecting and then connecting a column (or other component) isunproductive because the LC system is not in use and the operator isengaged in plumbing the system instead of preparing samples or othermore productive activities. Hence, the replacement of a column in aconventional LC system involves a great deal of wasted time andinefficiencies.

Given concerns about the need for leak-free connections, conventionalconnections have been made with stainless steel tubing and stainlesssteel end fittings. More recently, however, it has been realized thatthe use of stainless steel components in a LC system have potentialdrawbacks in situations involving biological samples. For example, thecomponents in a sample may attach themselves to the wall of stainlesssteel tubing. This presents problems because the detector's measurements(and thus the chromatogram) of a given sample may not accurately reflectthe sample if some of the sample's components or ions remain in thetubing, and do not pass the detector. Perhaps of even greater concern,however, is the fact that ions from the stainless steel tubing maydetach from the tubing and flow past the detector, thus leading topotentially erroneous results. Additionally, ions can easily bind tobiological compounds of interest, resulting in changes to the moleculesthat affect their retention time in the column. Hence, there is a needfor “biocompatible” connections through the use of a material that ischemically inert with respect to such “biological” samples and themobile phase used with such samples so that ions will not be released bythe tubing and thus contaminate the sample.

Multiport selector/injector valves are well known and have been used ina variety of industrial processes, such as liquid chromatography andmass spectrometry. For example, selection valves are commonly used inliquid chromatography and other analytical methods to direct fluid flowalong alternate paths. Such valves are also used to terminate fluidwithdrawal from one source and select another source of fluid, forexample, such as when a variety of streams in an industrial process isselectively sampled for analysis.

Injector/selector valves are often used in high pressure liquidchromatography (HPLC) or gas chromatography (GC). U.S. Pat. No.4,242,909 (Gundelfinger '909), which is hereby fully incorporated byreference, describes sample injection apparatus for withdrawing liquidsamples from vials and injecting them into a chromatographic column orother analyzing device. The apparatus is said to minimize wastage, crosscontamination, and dilution of the samples, and to be capable ofautomation with a minimum of complexity. Injector/selector valves areparticularly useful in chromatographic applications since a substantialamount of time and effort is required to set up a particular HPLC or GCsystem, which may often utilize multiple columns and/or multipledetection systems. Multiport selection valves permit the operator of thechromatograph to redirect flows such that particular samples areselected for injection into a particular column, or alternatively, todirect the output from a particular column to one or more differentdetectors.

As mentioned above, multiport selection valves have been known for sometime, including those which utilize a cylindrical rotor and statorcombination. In some of these valves, the stator holds the fluid tubesin fixed relation to each other and presents the tube ends to a rotorface which may contain a grooved surface. By varying the angle of therotor, the tubes are selectively brought into fluid communication. Onetype of injector/selector valve using a rotor/stator combination is theType 50 rotary valve from Rheodyne, Incorporated. The Type 50 valves aresaid to operate by rotation of a flat rotor against a flat stator (see“Operating Instructions for Type 50 Teflon Rotary Valves,” Rheodyne,Incorporated, printed in U.S.A. April 1994). Another rotor/statorselector valve is shown in U.S. Pat. No. 5,193,581 (Shiroto, et al.),which is hereby fully incorporated by reference. The valve is said tocomprise, among other things, a stator plate having a plurality ofoutlet holes extending through the stator plate and arranged in a circleconcentric with a valve casing, and a rotor having a U-shaped passageformed in the rotor. The rotor is said to be rotated through a desiredangle so that an inlet hole can be in fluid communication with selectedones of the outlet holes through the U-shaped passage of the rotor.

U.S. Pat. No. 5,419,419 (Macpherson) describes a rotary selector valvethat is used in connection with an automatic transmission in anautomobile. A motor is said to index a shear plate of the selector valveto predetermined positions for shifting the transmission. A series ofworking lines as shown in FIG. 6 are maintained in a closed spatialrelationship with the casing.

U.S. Pat. No. 3,494,175 (Cusick, et al.) discloses a valve having aplurality of capillaries which are held in spaced relationship within amanifold plate member. U.S. Pat. No. 3,752,167 (Makabe) discloses afluid switching device including a plurality of capillaries that areheld within threaded holes by couplings. A rotary member allows fluidcommunication between the tubes. U.S. Pat. No. 3,868,970 (Ayers, et al.)discloses a multipositional selector valve said to be adapted with ameans for attaching a plurality of chromatographic columns to the valve,such that the flow can be directed into any of the columns. U.S. Pat.No. 4,705,627 (Miwa, et al.) discloses a rotary valve said to consist oftwo stator discs and a rotor disposed between the two stator discs. Eachtime the rotor is turned intermittently it is said, different passagesare formed through which the fluid in the valve runs. U.S. Pat. No.4,722,830 (Urie, et al.) discloses multiport valves. The multiportvalves are said to be used in extracting fluid samples from sample loopsconnected with various process streams.

In many applications using selector/injector valves to direct fluidflows, and in particular in liquid and gas chromatography, the volume offluids is small. This is particularly true when liquid or gaschromatography is being used as an analytical method as opposed to apreparative method. Such methods often use capillary columns and aregenerally referred to as capillary chromatography. In capillarychromatography, both gas phase and liquid phase, it is often desired tominimize the volume of the fluid flowpath (e.g., length and/or size ofthe fluid pathways) of the valve. One reason for this is that a valvehaving a larger volume for the fluid flowpath will contain a relativelylarger volume of liquid, and when a sample is injected into the valvethe sample will be diluted, decreasing the resolution and sensitivity ofthe analytical method, and may result in a dead volume being introducedinto the fluid pathway.

Micro-fluidic analytical processes also involve small sample sizes. Asused herein, sample volumes considered to involve micro-fluidictechniques can range from as low as volumes of only several picolitersor so, up to volumes of several milliliters or so, whereas moretraditional LC techniques, for example, historically often involvedsamples of about one microliter to about 100 milliliters in volume.Thus, the micro-fluidic techniques described herein involve volumes oneor more orders of magnitude smaller in size than traditional LCtechniques. Micro-fluidic techniques can also be expressed as thoseinvolving fluid flow rates of about 0.5 ml/minute or less.

Most conventional HPLC systems include pumps which can generaterelatively high pressures of up to around 5,000 psi to 9,000 psi or so.In many situations, an operator can obtain successful results byoperating a LC system at “low” pressures of anywhere from just a few psior so up to 1,000 psi or so. More often than not, however, an operatorwill find it desirable to operate a LC system at relatively “higher”pressures of over 1,000 psi.

Another, relatively newer liquid chromatography form is Ultra HighPerformance Liquid Chromatography (UHPLC) in which system pressureextends upward to about 1400 bar or 20,000 psi or so, or even more. Inorder to achieve greater chromatographic resolution and higher samplethroughput, the particle size of the stationary phase has becomeextremely small. A stationary phase particle as small as 1 micron iscommon; the resulting high column packing density leads to substantiallyincreased system pressure at the head of the column. Both HPLC and UHPLCare examples of analytical instrumentation that utilize fluid transferat elevated pressures. For example, in U.S. Patent Publication No.2007/0283746 A1, published on Dec. 13, 2007 and titled “Sample InjectorSystem for Liquid Chromatography,” an injection system is described foruse with UHPLC applications, which are said to involve pressures in therange from 20,000 psi to 120,000 psi. In U.S. Pat. No. 7,311,502, issuedon Dec. 25, 2007 to Gerhardt, et al., and titled “Method for Using aHydraulic Amplifier Pump in Ultrahigh Pressure Liquid Chromatography,”the use of a hydraulic amplifier is described for use in UHPLC systemsinvolving pressures in excess of 25,000 psi. In U.S. Patent PublicationNo. 2005/0269264 A1, published on Dec. 8, 2005 and titled“Chromatography System with Gradient Storage and Method for Operatingthe Same,” a system for performing UHPLC is disclosed, with UHPLCdescribed as involving pressures above 5,000 psi (and up to 60,000 psi).Applicants hereby incorporate by reference as if fully set forth hereinU.S. Pat. No. 7,311,502 and US Patent Publications Nos. 2007/0283746 A1and 2005/0269264 A1.

As noted, liquid chromatography (as well as other analytical) systems,including HPLC or UHPLC systems, typically include several components.For example, such a system may include a pump; an injection valve orautosampler for injecting the analyte; a precolumn filter to removeparticulate matter in the analyte solution that might clog the column; apacked bed to retain irreversibly adsorbed chemical material; the HPLCcolumn itself; and a detector that analyzes the carrier fluid as itleaves the column. These various components may typically be connectedby a miniature fluid conduit, or tubing, such as metallic or polymerictubing, usually having an internal diameter of 0.001 to 0.040 inch.

All of these various components and lengths of tubing are typicallyinterconnected by threaded fittings. Fittings for connecting various LCsystem components and lengths of tubing are disclosed in prior patents,for example, U.S. Pat. Nos. 5,525,303; 5,730,943; and 6,095,572, thedisclosures of which are herein all incorporated by reference as iffully set forth herein. Often, a first internally threaded fitting sealsto a first component with a ferrule or similar sealing device. The firstfitting is threadedly connected through multiple turns by hand or by useof a wrench or wrenches to a second fitting having a correspondingexternal fitting, which is in turn sealed to a second component by aferrule or other seal. Disconnecting these fittings for componentreplacement, maintenance, or reconfiguration often requires the use of awrench or wrenches to unthread the fittings. Although a wrench orwrenches may be used, other tools such as pliers or other gripping andholding tools are sometimes used. It will be understood by those skilledin the art that, as used herein, the term “LC system” is intended in itsbroad sense to include all apparatus and components in a system used inconnection with liquid chromatography, whether made of only a few simplecomponents or made of numerous, sophisticated components which arecomputer controlled or the like. Those skilled in the art will alsoappreciate that an LC system is one type of an analytical instrument(AI) system. For example, gas chromatography is similar in many respectsto liquid chromatography, but obviously involves a volatile sample to beanalyzed, and uses a gas as a mobile phase. Such analytical instrumentsystems include high performance or high pressure liquid chromatographysystems, an ultra high performance or ultra high pressure liquidchromatography system, a mass spectrometry system, a microflowchromatography system, a nanoflow chromatography system, a nano-scalechromatography system, a capillary electrophoresis system, areverse-phase gradient chromatography system, or a combination thereof.Although the following discussion focuses on liquid chromatography,those skilled in the art will appreciate that much of what is said alsohas application to other types of AI systems and methods.

Increasing pressure requirements in liquid chromatography havenecessitated the use of high pressure fluidic components. For manyapplications regular stainless steel tubing can be used to withstand thehigh pressure. However, for some types of analyses (e.g., biologicaltesting and metal/ion analysis), stainless steel or other metals are notdesired in the fluid path as the metal could interfere with the testing.Additionally, there are some fields of use (e.g., nano-scale ornano-volume analysis), that require very small inside diameters toaccommodate the extremely low volumes required by these applications.Such small inside diameters are typically not available in stainlesssteel or other high pressure tubing.

In high-performance liquid chromatography (HPLC), ultra high-performanceliquid chromatography (UHPLC), and other high-pressure analyticchemistry applications, various system components and their fluidicconnections must be able to withstand pressures of 15,000 to 20,000 psior so. The types of fluidic connection systems between the tubes thatcarry fluids and the ports that receive fluids in these high-pressureapplications are limited. Many fluidic connection systems rely oncone-shaped, threaded, or welded fittings to attach a tube to areceiving port. These types of connections sometimes may have drawbacks,however. For example, the size of cone-shaped fittings and threadedfittings are dependent on the type and size of any given port, whichmakes quickly interchanging a tube fitted with a particular cone orthreaded fitting between various ports difficult. Othercompression-based fittings have been employed to address this problem.Such fittings often employ a ferrule or a lock ring to help secure oneend of a tube to a receiving port. However, ferrules and lock rings canbecome deformed after multiple uses (e.g., by connecting, disconnecting,and reconnecting to various ports). This is especially true inhigh-pressure applications, where a fluid-tight seal is essential, andwhere a ferrule or lock ring may be more likely to become deformed increating such a seal.

For example, published U.S. Patent Application No. 2013/0043677, titled“Tube and Pipe End Cartridge Seal,” published on Feb. 21, 2013,describes a tube and pipe end cartridge seal for use at high pressures,which relies on a fitting body (including ferrule fittings) toeffectuate a seal with the axial end of a tube. Moreover, a dimple isforged on the annular end of the tube face to further effectuate theseal. Likewise, U.S. Pat. No. 6,056,331, titled “Zero Dead Volume Tubeto Surface Seal,” issued to Bennett et al. on May 2, 2000, describes anapparatus for connecting a tube to a surface using a body, a ferrule,and a threaded fitting. Although Bennett et al. discloses a type of tubeface-sealing apparatus, the apparatus of Bennet et al. relies on athreaded fitting and a ferrule. Similarly, published U.S. PatentApplication No. 2012/0061955, titled “Plug Unite and Connection Systemfor Connecting Capillary Tubes, Especially for High-Performance LiquidChromatography,” published on Mar. 15, 2012, discloses a plug unitconnection system for capillary tubes, wherein a seal is provided at theinterface between a capillary tube and a bushing unit, instead of at thelocation of a ferrule or conical fitting. However, U.S. PatentApplication No. 2012/0061955 relies on the use of a pressure piecesimilar to a ferrule to ensure that enough axial force can be generatedto obtain a seal at the tube face.

Connection assemblies which attempt to effectuate a seal forhigh-pressure applications can require a significant amount of torque toeffectuate a fluid-tight seal, making the creation of such sealsdifficult without the use of additional tools and increasing the risk ofdamage to the fitting assembly or its components due to overtightening.Moreover, experience suggests that many users do not like to use varioustools to connect or disconnect tubing from components such as those invarious AI systems. It is believed that users often apply differentamounts of torque to connect or disconnect tubing and the components insuch systems, thus resulting in potential problems caused byover-tightening or under-tightening (e.g., leakage or loss of sealingwhen the fluid is under pressure).

One example of a flat-bottomed or face-sealing connection assembly isprovided by U.S. Pat. No. 8,696,038, titled “Flat Bottom FittingAssembly” and issued on Apr. 15, 2014 to Nienhuis. Nienhuis teaches atype of flat bottom assembly which includes a flat-sided ferrule, andwherein the assembly including the ferrule and the tube can be pressedagainst a flat bottom port. Another example of a flat-bottomed orface-sealing connection assembly is provided by published U.S. PatentApplication No. 2012/0024411, titled “Biocompatible Tubing for LiquidChromatography Systems,” which was published on Feb. 2, 2012 and wasfiled on behalf of Hahn et al. The Hahn et al. published patentapplication describes tubing having an inner layer and an outer layer,and in which the inner layer can be biocompatible material such aspolyetheretherketone (PEEK) and the outer layer may be a differentmaterial, and in which an end of the tubing may be flared or otherwiseadapted to have a larger outer diameter than other portions of thetubing. The current state of the art for high pressure connections inboth HPLC and UHPLC is to utilize coned ports along with some form offerrule and nut combination with tubing. The nut translates rotationaltorque into axial load that is translated to the ferrule. The loadcauses the ferrule to deform/deflect and grip the tubing, creating aseal. The tube is typically forced into the bottom of the coned port,but there is not currently a mechanism to ensure there is not a gap orspace at the port bottom.

The space at the bottom of the port is a concern for those performingliquid chromatography experiments due to the potential to negativelyinfluence the results with carry over and band broadening. Carry over isjust as it sounds, analyte from one test is carried over to the next.Carry over can produce very unstable results for obvious reasons. Bandbroadening is when the peaks identifying a substance become lesssymmetric and make identification more difficult when peaks of differentmolecules have similar retention times.

One issue with conventional ferrules used with coned ports is that thetorque required to deform/deflect is typically above finger tight levelsin order to achieve UHPLC pressures (e.g., above 12,000 psi or so). Itis desirable to remove tools from the lab by making them unnecessary formaking and breaking fluidic connections and it is advantageous to havefittings that can be connected simply with the fingers rather thantools.

European Patent No. EP 2564104 describes a sealing system for use athigh pressure. End-face seals minimize the sealing radius and thereforeallow various fittings—including known ferrule fittings—to be used inhigh-pressure systems. End-face seals at such high pressure may requiresmooth surfaces, however. In order to reduce cost, an end-facepreparation tool may be required to forge a dimple into the end face tomechanically deform and smooth the surface.

U.S. Pat. No. 6,056,331 describes an apparatus that is composed of threecomponents, a body, a ferrule, and a threaded fitting. The ferrule iscompressed onto a tube and a seal is formed between the tube and adevice retained in the body by threading the fitting into the body whichprovides pressure that seals the face of the ferrule to a mating surfaceon the device. This seal may be used at elevated temperatures, dependingon the materials used. This fitting was developed for use withmicro-machined silicon wafers used in capillary gas chromatography.

In many conventional valves, such as rotary shear valves, a statormember at one end has two or more ports to receive tubing which can beremovably attached to provide fluid connections to the valve. Such astator member typically serves as least two functions: it provides aplanar stator face which mates with a rotor seal, and also providesfluid channels or pathways between the ports and the stator face. Intypical such valves, the stator member is a single piece and is oftendesigned so that the ports to receive the tubing are oriented at angleswith respect to the longitudinal axis of the stator member and the valvegenerally. This approach is generally due to the need to provide severalports on the end surface of the stator member, as well as several screwsor nuts to secure the stator member to the valve body, and the limitedsize of the stator member and the resulting limited space available forthe ports, as well as the need to allow enough space for an operator toconnect and disconnect tubing from the ports of the stator member. Anexample of a valve with such a single-piece stator is described andshown in U.S. Pat. No. 8,905,075 B2, issued on Dec. 9, 2014, to Tower,and entitled “Rotary Shear Valve Assembly with Hard-on-Hard SealSurfaces,” which is hereby incorporated by reference as if fully setforth herein.

While this configuration has worked in the past, and still works formany applications, it also typically requires that the fluid passagewaysbetween the ends of the tubing and the stator face are longer andtherefore have a greater volume than may be desired. Those skilled inthe art will appreciate that the volumes in valves used for analyticalscience applications generally require very precise control over thevolumes of the fluid passageways, and the use of smaller and smallersample sizes means that the precise control of such volumes can becomeimportant. In addition, stator members of this type are often made ofmetal, such as stainless steel, and the manufacturing and machining ofsuch stator members can be costly and time consuming. The use of angledports tends to require that the stator member be larger in size, andthis also tends to increase the costs of such stator members. Inaddition to these issues, the alignment of the fluid flowpaths of thecomponents once assembled can be problematic with such conventionalstator members. It will be appreciated that the tubing will have aninner diameter through which the fluid flows, and the ports of thestator member will likewise have openings at the bottom of the ports,with those openings providing fluid passageways. If the stator membersurface has been lapped during manufacturing, which is often the case,then the openings of the ports may shift in shape, size or location,thereby causing potential difficulties in the alignment of the openings;the alignment of the openings is usually desired in order to preventturbulent fluid flow.

U.S. Pat. Nos. 3,494,175, 3,752,167, 3,868,970, 4,242,909, 4,705,627,4,722,830, 5,193,581, 5,419,419, 5,525,303, 5,730,943, 6,056,331,6,095,572, 7,311,502, 7,811,452, 8,071,052, 8,696,038, European PatentNo. EP2564104, and published U.S. Patent Application Nos. 2005/0269264,2007/0283746, 2009/0321356, 2010/0171055, 2012/0024411, 2012/0061955,2013/0043677, and 2016/0116088 are hereby incorporated by reference asif fully set forth herein.

SUMMARY OF THE INVENTION

The present disclosure in one embodiment provides a valve with atwo-piece stator assembly useful for use with, among other applications,high pressure liquid chromatography or other analytical instrumentsystems. In one embodiment, a separate and removable stator plate isprovided and is adapted to engage with a mounting device to provide atwo-piece stator assembly for one end of a valve. The mounting device isadapted on one side to engage and contact one side of the stator plate,and on the other side includes a plurality of ports for receiving aplurality of fitting assemblies for fluidic connections via tubing. Theports of the mounting device are in fluid communication with one or morefluid pathways in the stator plate and/or one or more fluid pathways ina rotor seal located on the second side of the stator plate. By makingthe stator face a separate and replaceable component distinct from themounting device, a number of advantages are achieved, includingproviding greater flexibility for the use of the valve in variousapplications, reducing the overall costs of the valve, allowing the useof different materials for the mounting device and the stator plate, andothers as described below. Although different configurations for theports of the mounting device and for fitting assemblies used toremovably secure tubing in the ports of the mounting device may be used,flat-bottomed ports adapted to removably hold face-sealing fittingassemblies provide advantages (as described in more detail below).

In one embodiment, a high-pressure valve for liquid chromatography isprovided comprising a mounting plate having a first side and a secondside, and having a plurality of openings therethrough, wherein each ofthe plurality of openings is adapted to removably receive tubing in thefirst side of said mounting plate, as well as a stator plate having afirst side and a second side, wherein the first side of said statorplate is adapted to engage with the second side of said mounting plate,wherein said stator plate has a plurality of openings in the first sideand second side of said stator plate, and at least a plurality of theopenings in the second side of said mounting plate are in fluidcommunication with corresponding openings in the first side of saidstator plate, and wherein said stator plate and said mounting plate areremovably attached to one another. The valve also includes a rotor sealadapted to engage with at least one of the first side and second side ofsaid stator plate, a rotor shaft which is rotatable around alongitudinal axis, and a housing within which the rotor seal and atleast a portion of said rotor shaft are located, wherein said mountingplate and said stator plate are removably attached to said housing. Thevalve may have a mounting plate which comprises a first material and astator plate which comprises a second material. The stator plate cancomprise a metal, a biocompatible material, and/or a ceramic material,or a combination thereof. The plurality of openings in said mountingplate can further comprise flat-bottomed ports for removably receivingtubing, and the first side of said stator plate can further comprisebosses aligned to extend partially into the bottom of the ports of saidmounting plate. The stator plate may comprise a plurality of layersbonded together, such as by diffusion bonding. The mounting plate maycomprise one or more of aluminum, copper, steel, stainless steel,titanium, polyetheretherketone, polypropylene, polysulfone, DELRIN,ULTEM, polyphenylen sulfide (PPS), polytetrafluoroethylene, nylon,polyamides, or a combination thereof. The stator plate also may comprisea plurality of layers bonded together, such as by diffusion bonding,wherein at least one of said layers comprises one or more of stainlesssteel, titanium, MP35N, ceramics, glass, or a combination thereof. Insome embodiments, the stator plate may further comprise a guide layer,wherein the guide layer comprises openings with a greater width than theopenings of the layer below the guide layer and the guide layer isadapted to be adjacent to the second side of said mounting plate. Inaddition, the stator plate can be designed and adapted to be removablefrom said mounting device and the valve. A valve according to thepresent disclosure can be adapted to operate with fluid pressures of afluid flowing therethrough of at least 1,000 psi, 5,000 psi, 10,000 psi,15,000 psi, 20,000 psi, and/or 25,000 psi.

In one embodiment, a removable stator plate for a high-pressure valvefor an analytical instrument system is provided, wherein said statorplate comprises a first side, a second side, with each of the first sideand the second side having a plurality of openings, and a plurality ofpassageways therethrough wherein each of the passageways provides fluidcommunication between at least one opening on the first side and atleast one opening on the second side of said stator plate, and whereinsaid stator plate comprises a plurality of layers bonded together bydiffusion bonding, and wherein the first side of said stator plate isadapted to sealingly engage with one side of a mounting plate, which isadapted to receive and sealingly hold a plurality of tubes, and thesecond side of said stator plate is adapted to sealingly engage with oneside of a rotor seal of a valve, and said stator plate and said mountingplate are adapted to be removably attached to a body of a valve. Thestator plate may comprise one or more biocompatible materials, and maycomprise four layers, with at least two layers bonded together bydiffusion bonding. In one embodiment, the first side of said statorplate may comprise at least four openings and at least two passagewaystherethrough. The stator plate may also further comprise one or more ofthe following analytical instrument system: a sample loop, a mixingelement, a column, a filter, a heating element, a sensor, or a detector.The stator plate may be adapted to be removed from a valve and replacedby a second stator plate, wherein said second stator plate comprises adifferent material than said stator plate, and/or the stator plate maybe adapted to be removed from a valve and replaced by a second statorplate, wherein said second stator plate comprises one or more differentanalytical instrument system elements than said stator plate.

In another embodiment, an analytical instrument (AI) system, such as aliquid chromatography system, is provided which comprises a valvecomprising (a) a mounting plate having a first side and a second side,and having a plurality of openings therethrough, wherein each of theplurality of openings is adapted to removably receive tubing in thefirst side of said mounting plate, and (b) a stator plate having a firstside and a second side, wherein the first side of said stator plate isadapted to engage with the second side of said mounting plate, whereinsaid stator plate has a plurality of openings in the first side andsecond side of said stator plate, and at least a plurality of theopenings in the second side of said mounting plate are in fluidcommunication with corresponding openings in the first side of saidstator plate, and wherein said stator plate and said mounting plate areremovably attached to one another. The AI system may have a stator plateand a mounting plate which are adapted to be removably attached to oneanother, the valve may be adapted to operate with fluid pressures of atleast 1,000 psi, 5,000 psi, 10,000 psi, 15,000 psi, 20,000 psi, or25,000 psi.

In yet another embodiment of the present disclosure, a stator assemblyfor a high-pressure valve is described that comprises a mounting platehaving a first side and a second side, and having a plurality ofopenings therethrough, wherein the first side of each of the pluralityof openings is located in the first side of said mounting plate and isadapted to removably receive tubing therein, and a stator plate having afirst side and a second side, wherein the first side of said statorplate and the second side of said mounting plate are adapted tosealingly engage with one another, wherein said stator plate has aplurality of openings in the first side and second side of said statorplate, and at least a plurality of the openings in the second side ofsaid mounting plate are in fluid communication with correspondingopenings in the first side of said stator plate, and wherein saidmounting plate and said stator plate are adapted to be removablyattached to one another. The stator assembly may have the plurality ofopenings in the second side of the mounting plate and the correspondingopenings in the first side of said stator plate aligned with oneanother.

In still another embodiment, methods of use and operation of a valvewith a removable and replaceable stator plate are described, involvingthe disassembly of a valve having a stator plate, removing a firststator plate and replacing it with a second stator plate, thenreassembling the valve by reattaching the second stator plate and themounting device to the valve.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an exploded isometric view of certain of the components of avalve in one embodiment in accordance with the present disclosure.

FIG. 2 is a partial cross-sectional view of a valve in one embodiment inaccordance with the present disclosure.

FIG. 3 is an isometric view of a valve in one embodiment in accordancewith the present disclosure.

FIG. 4 is a partial cross-sectional view of a valve in anotherembodiment in accordance with the present disclosure.

FIG. 5 is a partial cross-sectional view of a valve in anotherembodiment in accordance with the present disclosure.

FIG. 6 is an enlarged partial cross-sectional view of a valve in anotherembodiment in accordance with the present disclosure.

FIG. 7 is an exploded isometric view of the portions of a stator platein another embodiment in accordance with the present disclosure.

FIG. 8 is an exploded isometric view of the portions of a stator platein another embodiment in accordance with the present disclosure.

FIG. 9 is an exploded isometric view of the portions of a stator platein another embodiment in accordance with the present disclosure.

FIG. 10 is an isometric view of a stator plate in an embodiment inaccordance with the present disclosure.

FIG. 11 is an enlarged cross-sectional view of a stator plate andmounting device in an embodiment in accordance with the presentdisclosure.

FIG. 12 is an isometric view of a stator plate and mounting device in anembodiment in accordance with the present disclosure.

FIG. 13 is an enlarged cross-sectional view of a stator plate andmounting device in another embodiment in accordance with the presentdisclosure.

FIG. 14 is a top view of a stator plate in accordance with an embodimentof the present disclosure.

FIG. 15 is a bottom view of a stator plate in accordance with anembodiment of the present disclosure.

FIG. 16 is a cross-sectional view of a stator plate of FIG. 14 takenalong line A-A.

FIG. 17 is an enlarged view of a portion of the stator plate of FIG. 14.

FIG. 18 is a cross-sectional view of the stator plate of FIG. 15 takenalong line C-C and an enlarged portion thereof.

FIG. 19 is an isometric view of a mounting device in an embodiment inaccordance with the present disclosure.

FIG. 20 is a top view of the mounting device of FIG. 19.

FIG. 21 is a cross-sectional view of the mounting device of FIG. 19taken along line A-A of FIG. 20.

FIG. 22 is a cross-sectional view of the mounting device of FIG. 19taken along line B-B of FIG. 20.

FIG. 23 is a bottom view of the mounting device of FIG. 19.

DETAILED DESCRIPTION

Referring to FIG. 1, the key components of a valve 1 in one particularembodiment are shown in an exploded view. The valve 1 includes a rotorshaft 5, a bearing ring 10, a compliant PEEK spring 15, a rotor seal 20,a stator ring 25, a stator plate 30, a mounting device 35, a pluralityof screws 40, and fitting assemblies with tubing therein 45. Across-sectional view of a portion of the valve 1 is provided in FIG. 2,with the various components assembled. As shown in FIG. 2, the valve 1includes a rotor shaft 5, rotor seal 20, stator plate 30, and mountingdevice 35, as well as a housing 4 and, located within the housing 4 andaround a portion of rotor shaft 5 is a spring 11. (Screws 40 are notshown in FIG. 2, but it will be appreciated by those skilled in the artthat the screws 40 are used to attach the mounting device 35 and statorplate 30 to the stator ring 25, which attachment may be either removableor permanent.)

As shown in FIGS. 1 and 2, each of the rotor shaft 5, bearing ring 10,spring 15, rotor seal 20, stator ring 25, stator plate 30, and mountingdevice 35 are generally circular in a transverse direction and, with theexceptions described below (such as in the stator plate 30 and in theuse of three screws 40), each of such components is generally symmetricaround the longitudinal axis of the valve 1 and generally define acylindrical shape. As shown in FIG. 2, the rotor seal 20, the rotorshaft 5, and the spring 11 are located within the body of the valve 1 asprovided by the stator ring 25 and the housing 4. Although the valve 1shown and described herein is a rotary valve, those skilled in the artwill appreciate that the embodiments of the present disclosure mayinclude other valves as well. For purposes of brevity, the presentdisclosure focuses on a rotary valve.

As shown in FIG. 2, each of the mounting device 35, stator plate 30,rotor seal 20, and stator ring 25 have two surfaces, each of which issubstantially planar in a transverse direction. For convenience of thereader, these may be referred to as the “top” and “bottom” surfaces withreferences to the figures. However, those skilled in the art willunderstand that in fact the valve 1 may have any orientation in use andthat the top and bottom of the various components as shown in FIG. 2,for example, may be reversed or may vary in any given use, and that allsuch orientations are within the scope of the present disclosure. Asshown in FIG. 2, the top surface of the stator ring 25 is in contactwith portions of the bottom surface of the stator plate 30. In addition,a portion of the top surface of the rotor seal 20 is in contact with acentral portion of the bottom surface of the stator plate 30. The topsurface of the stator plate 30 is in contact with the bottom surface ofthe mounting device 35.

The mounting device 35 includes openings or ports for removablyreceiving tubing 46 and fitting assemblies 45, each of which may includea nut 47, a sleeve 48 and a sealing tip 49. Such fitting assemblies aredescribed in more detail in co-pending U.S. patent application Ser. No.14/922,041, which was published as United States Published PatentApplication No. 2016/0116088 A1, and the entirety of which is herebyincorporated by reference as if fully set forth herein. For purposes ofbrevity, details regarding the nut 47, sleeve 48, and sealing tip 49 arenot provided herein, as a full and detailed description is available tothe reader in U.S. Published Patent Application No. 2016/0116088 A1.

It will be appreciated that the use of a fitting assembly like thatshown and described in detail in U.S. Published Patent Application No.2016/0116088 A1 in connection with the novel mounting device 35 andstator plate 30 as shown and described herein provides a number ofsubstantial advantages. For example, the use of such fitting assemblieswith the mounting device 35 and stator plate 30 allow the tubing to besealingly engaged with the mounting device 35 and the stator plate 30 inan essentially vertical position with respect to the longitudinal axisof the tubing and the substantially planar bottom surface of themounting device 35 and substantially planar top surface of the statorplate 30. In the past, conventional stators for high pressure valvestypically had fluid pathways and ports which were at angles of between15 and 60 degrees with respect to the substantially planar bottomsurface of the stator, such as can be seen in U.S. Pat. No. 5,419,208,for example. By allowing for an essentially vertical or perpendicularconnection of the tubing (e.g., between about 80 degrees to 100 degreeswith respect to the transverse axis of the stator plate), the mountingdevice 35 and stator plate 30 allow for sealing the end of the tubingadjacent to or very close to the top surface of the stator plate 30. Inaddition, this approach means that the costly, and time-consumingmachining required to manufacture conventional stators is not requiredfor the mounting device 35 of the present disclosure. Such machining wascostly due to the precision needed to make such ports and fluid pathwaysin conventional stators. However, the precision required for themounting device 35 of the present disclosure is much less and mucheasier to achieve without the costly and time-consuming machiningrequired for conventional stators. Those skilled in the art willunderstand, however, that any one of a variety of different fittingassemblies may be used to removably and sealingly attach tubing 46 tothe valve 1 via the ports in the mounting device 35, and thatflat-bottomed fitting assemblies (such as may be commercially availablefrom a variety of manufacturers, including but not limited to theMarvelX fitting assembly from IDEX Health & Science LLC) will likelyprovide advantages over fitting assemblies with a conical ferrule andcone-shaped port configuration (although the latter may be used with themounting device 35 and stator plate 30 if desired).

Also shown in FIG. 2 are fluid passageways 52 and 54 located in statorplate 30. Each of passageways 52 and 54 provide a fluid pathway betweenone of the openings (e.g., a bottom of a port) in the mounting device35, through a corresponding opening in the top surface of the statorplate 30, and to a central opening on the bottom of the stator plate 30.The rotor seal 20 in FIG. 2 includes a channel 21, which provides afluid pathway to connect the opening on the bottom face of stator plate30 corresponding to pathway 52 with at least one other opening in thebottom face of stator plate 30. It will be appreciated that thecomponents of the valve 1 are expected to be attached or in contact withone another so that they form a sealing engagement, even when the fluidflowing through tubing 46 and passageways 52 and 54 is flowing at veryhigh pressures. Spring 11 provides a compressive force against the rotorshaft 5 and urges the top side of rotor shaft 5 against the bottom sideof the rotor seal 20, and thus the top side of rotor seal 20 against thebottom side of the stator plate 30.

The passageways 52 and 54, as well as the channels 21 may be of variousshapes and sizes. For example, the passageways 52 and 54 and/or channels21 may be circular in cross section, a hemisphere in cross section,D-shaped in cross section, square shaped in cross section, and so forth.Passageways 52 and 54 and/or channels 21 can also have different sizesor shapes from one another if desire, such that passageway 52 has afirst shape and/or size and passageway 54 has a second shape and/orsize, for example. Although FIG. 2 shows passageways 52 and 54 locatedwithin stator plate 30, it will be appreciated that fluid pathways canbe provided as a groove on the bottom face of the stator plate 30, asthe top side of rotor seal 20 will close or seal such grooves when thevalve 1 is fully assembled. Alternatively, fluid pathways can beprovided as one or more grooves or channels 21 on the top side of therotor seal 20, and in addition a combination of passageways and/orgrooves on the top and/or bottom sides of the stator plate 30 can beprovided. Moreover, those skilled in the art will appreciate that,although FIG. 2 shows two passageways 52 and 54, and one channel 21,more or less passageways (or grooves, as the case may be), and/orchannels in rotor seal 20, can be provided in valve 1.

Although not shown, those skilled in the art will appreciate that thestator plate 30 may comprise one or more analytical instrumentcomponents, such as a sample loop, a splitter, a mixer, a column, atemperature, fluid flow, or pressure sensor, a filter, a heatingelement, a detector, and other types of micro-electro mechanical systemscomponents. Techniques for adding such components to a substrate withthe use of diffusion bonding that may be useful in manufacturing astator plate 30 having one or more such components are detailed in U.S.Published Patent Application No. 2016/0169843 A1, which was published onJun. 16, 2016, and is entitled “Pressure Sensing and Flow Control InDiffusion-Bonded Planar Devices for Fluid Chromatography,” which ishereby incorporated by reference herein as if fully set forth herein.

In FIG. 3, an isometric view of an assembled valve 1 is provided. Asshown in FIG. 3, the valve 1 includes the mounting device 35, the statorring 25, and also valve body 3 and a knob 2. The knob 2 can be attachedto one end of a rotor shaft 5, and that when the knob 2 is turned, therotor shaft 5 and rotor seal 20 are also turned or rotated. It will alsobe appreciated that some or all of the fluid pathways and/or passageways(however shaped or whether grooves or passageways, etc.) may be coatedwith one or more coatings. Coatings may be added to such fluid pathwaysto reduce friction, increase hardness, provide biocompatibility (orenhance existing biocompatibility), provide better chemicalcompatibility, and the like, all as may be desired for one or moreparticular applications of the valve 1. For example, it may be desirableto have the fluid pathways coated with a particular chemical substanceif the intended application involves the use of a corrosive chemical, orto have biocompatible fluid pathways if the intended applicationinvolves biological samples and biocompatibility is a concern.

Among other advantages of a valve with the two-piece mounting device 35and stator plate 30 as described herein, the mounting device 35 can bemade of plastics or metal because the mounting device 35 does not form apart of the fluid flowpath and does not come into contact with thefluid. For example, the mounting device 35 can be made of plastics, suchas PEEK, PPS, DELRIN, PP, PS, ULTEM, and the like, or the mountingdevice 35 can be made of metal, such as aluminum, copper, steel,stainless steel, titanium, MP35N, or alloys of various metals, or ofceramic materials or other composite materials. As long as the statorplate 30 is made of one or more biocompatible materials, the valve 1 canstill provide a biocompatible flowpath and the valve 1 can be used forbiocompatible applications. Another advantage of the two-piece assemblyis that the mounting device 35 can be made of a cheaper material, suchas for those applications in which higher pressures are not used, and itcan be reusable. Thus, the valve 1 of the present disclosure provides agreat deal of flexibility in terms of materials and potential uses, aswell as cost savings and ease of manufacturing.

Although not shown, it will be appreciated that either or both of thesubstantially planar surfaces of the stator plate 30 may be lappedand/or coated with a diamond-like carbon (DLC) or other coatingmaterial, and the substantially planar surface of the mounting device 35which abuts one surface of the stator plate 30 may also be lapped and/orcoated with DLC or another coating material. Such lapping and/or coatingcan be used to reduce friction and increase hardness and to provide avery smooth surface to provide a better fit and engagement of themounting device 35 and one side of stator plate 30 and the rotor seal 20and the second side of the stator plate 30, respectively.

Another advantage of the valve 1 with the two-piece stator assembly withthe mounting device 35 and the stator plate 30 is that the stator plate30 can be removed and replaced with a different stator plate 30. Forexample, if a first stator plate 30 has been used extensively and startsto become worn or provides less precise results, the first stator plate30 can be replaced without requiring a new valve or even a new mountingdevice 35. For example, an operator can disassemble the valve 1 with aworn stator plate 30 by unscrewing the three screws 40 and removing thestator plate 30 and the mounting device 35 from the stator ring 25 ofthe valve 1. The worn stator plate 30 can then be detached from themounting device 35 and a new stator plate 30 can be attached to replacethe worn stator plate 30, and then the operator can reassemble the valve1 by aligning the stator plate 30 and the mounting device 35 withlocation pins (not shown) and then securely attaching the stator plate30 and the mounting device 35 to the stator ring 25 and valve 1 byscrewing the screws 40 into place in the body of the valve 1 to securelyattach the mounting device 35 and new stator plate 30 to the rest of thevalve 1. This provides the advantage of replacing the stator plate 30without replacing any other components of valve 1, thereby providinglonger life and cheaper costs of use of the valve 1.

Moreover, the stator plate 30 and/or mounting device 35 can be replacedwith these methods so that an alternative stator plate 30 and/oralternative mounting device 35 can be used for a desired application.Because analytical instrument systems can be complicated, allowing anoperator to simply replace a stator plate 30 and/or mounting device 35for a given application of the valve allows the operator to useessentially the same valve 1 for a variety of applications. For example,an operator may wish to use a metallic mounting device 35 and a metallicstator plate 30 in combination for a particular application, such as oneinvolving high pressures. If the operator then desires to use the valve1 in an application in which biocompatibility is desired, the operatorcan then replace either or both of the stator plate 30 and the mountingdevice 35 with a stator plate and/or mounting device which are made frombiocompatible materials. In addition, an operator can replace a statorplate 30 for an application in which it is desired that the stator platehave a particular size of sample loop, a mixer, a pressure, flow, ortemperature sensor, or the like so that the replacement stator plate 30includes the desired feature for the desired application, all withoutrequiring a completely separate valve 1. Such flexibility will providethe operator with the advantages of reduced costs (due to less need foradditional valves or replacement valves), longer valve life, ease of useacross a variety of applications, and the ability to provide changes tothe valve relatively quickly (such as by changing the stator plateand/or mounting plate in a valve without entirely replacing orrelocating the valve within the analytical instrument system).

Referring now to FIG. 4, an alternative embodiment of valve 1′ is shown.(It will be appreciated that for the convenience of the reader, likecomponents and features in various drawings will have the same numbers.)The valve 1′ includes a mounting device 35 and is shown with four tubes46 connected to four ports therein. The valve 1′ further has a rotorshaft 5 and a rotor seal 20. Instead of the stator plate 30 shown inFIGS. 1-3, the valve 1′ in FIG. 4 has a guide layer 32 and a statorplate 30. The guide layer 32 provides a guide surface to help guide thetip of the tubing 46 into the guide layer 32 and into contact with thetop surface of the stator plate 30.

In FIG. 5, the valve 1′ is shown. However, in FIG. 5, the tubing 46′,nut 47′, sealing tip 49′ and sleeve 48′ are provided. Thus, FIG. 5illustrates an alternative embodiment in which an alternative fittingassembly may be used, even though no change to the mounting device 35,guide layer 32 or stator plate 30 (or other components) of valve 1′ isrequired. A commercially available fitting assembly like that shown inFIG. 5 can be provided by the VIPER brand fitting assembly from DionexCorporation of Sunnyvale, Calif.

FIG. 6 provides an enlarged partial cross-sectional view of theinterface between the mounting device 35, the guide layer 32, and thestator plate 30. As shown in FIG. 6, tubing 46 with a central fluidpassageway 52 is shown located within a passageway through sleeve 48. Atthe bottom end of the tube 46, a sealing tip 49 is provided, with abottom portion of the sleeve 48 surrounding the bottom outer surfaceportion of the sealing tip 49. As also shown in FIG. 6, the bottom endsurface of the sealing tip 49 is in contact with the top surface of theguide layer 32. The guide layer 32 has an opening 32 b therein which isadapted to snugly receive therein at least a portion of the bottom ofthe tube 46, sleeve 48, and sealing tip 49. In addition, the opening 32b in the guide layer 32 has a portion 32 a which has a wider innerdiameter than the bottom portion of the opening 32 b. This wider portion32 a (which is generally frustoconical in shape) helps align thecombination of the sealing tip 49, sleeve 48, and tube 46 so that thepassageway 52 of the tube 46 is in good alignment with the opening 32 bin the stator plate 30.

Turning now to FIG. 7, an exploded isometric view of a series of layers30 a′, 30 b′, 30 c′ and 30 d′ are shown, which together can form statorplate 30′. In FIG. 7, it can be seen that layer 30 a′ has an opening 41a, which is one of six openings which are located in a circular patternproximal the center of the layer 30 a′. Also shown in FIG. 7 withrespect to layer 30 a′ are two openings 43, through which location pins(not shown) are located when the valve is assembled. It can be seen thateach of layers 30 b′, 30 c′, and 30 d′ has openings which correspond toand align with the openings 43 of the layer 30 a′. In addition, (andamong the other openings and fluid pathways shown in FIG. 7) layer 30 b′has an opening 41 b, layer 41 c has a pathway 41 c, and layer 30 d′ hasan opening 41 d. It will be appreciated from FIG. 7 that openings 41 a,41 b, the ends of pathway 41 c, and opening 41 d, respectively, arealigned and correspond to one another, thus providing a fluid pathwaytherebetween. Those skilled in the art will understand that, althoughnot described in detail for purposes of brevity, the other openings andchannels shown in FIG. 7 are aligned and correspond to respectiveopenings and at least one channel in layers 30 a′, 30 b′, 30 c′, and 30d′.

In FIG. 8, an alternative stator plate 30″ is shown in an explodedisometric view. The stator plate 30″ includes layers 30 a″, 30 b″, 30c″, and 30 d″. In this particular embodiment, the main differencebetween it and the embodiment of stator plate 30′ shown in FIG. 7 isthat the stator plate 30″ includes a layer 30 c″ in which grooves orfluid pathways are shown in a different configuration from that shown inFIG. 7. In FIG. 8, it can be seen that layer 30 a″ has an opening 41 a′,which is one of six openings which are located in a circular patternproximal the center of the layer 30 a″. Also shown in FIG. 8 withrespect to layer 30 a″ are two openings 43, through which location pins(not shown) are located when the valve is assembled. It can be seen thateach of layers 30 b″, 30 c″, and 30 d″ has openings which correspond toand align with the openings 43 of the layer 30 a″. In addition, (andamong the other openings and fluid pathways shown in FIG. 8) layer 30 b″has an opening 41 b′, layer 41 c′ has a pathway 41 c′, and layer 30 d″has an opening 41 d′. In addition, layer 30 c″ has a sample loop 42provided by a channel connecting channel 41 c′ with a correspondingchannel opposite thereto. It will be appreciated from FIG. 8 thatopenings 41 a′, 41 b′, the ends of pathway 41 c′ and sample loop 42, andopenings 41 d′ and 41 d″, respectively, are aligned and correspond toone another, thus providing a fluid pathway therebetween. Those skilledin the art will understand that, although not described in detail forpurposes of brevity, the other openings and channels shown in FIG. 8 arealigned and correspond to respective openings and at least one channelin layers 30 a″, 30 b″, 30 c″, and 30 d″.

FIG. 9 provides yet another alternative embodiment of a stator plate30′″ in an exploded isometric view. In FIG. 9, a stator plate 30′″ isshown, which includes five pieces or slices 30 a′″, 30 b′″, 30 c′″, 30d′, and 30 e′″. As shown in FIG. 9, the pieces 30 b′″ and 30 c′″ providedifferent fluid pathway configurations than those shown and provided bythe stator plate 30′ or the stator plate 30″ shown in FIGS. 7 and 8,respectively, including among other things a sample loop 42′ in layer 30c′″. Those skilled in the art will appreciate that features such as butnot limited to sample loops may have different sizes, lengths, patters,and volumes, among other things, as may be desired for a givenapplication, and that there are many other configurations of the fluidpathways and fluid connections that can be provided with a stator plate30 beyond the various particular embodiments shown in FIGS. 7-9, forexample.

The different layers 30 a′″, 30 b′″, 30 c′″, 30 d′″, and 30 e′″, forexample, can be attached and combined into a single stator plate 30′(such as shown in FIG. 10) by diffusion bonding. The plurality of holesin each of the layers and also the grooves or fluid pathways in each ofthe layers 30 b′″ and 30 c′″, for example, can be etched into the layersso that the holes and grooves or pathways are very precisely located andof very precise sizes and shapes. The stator plate 30′″ shown in FIG. 10further includes an annular ring shape with a thicker width than theinterior portion of the stator plate 30″. Such an annular ring shape canbe obtained by machining or etching the combination of the layers 30a′″, 30 b′″, 30 c′″, 30 d′, and 30 e′″ into the stator plate 30′″.

If layers 30 a′″, 30 b′″, 30 c′″, 30 d′″, and 30 e′″ are made of ametal, such as titanium or any of the metals or alloys noted above, suchlayers 30 a′″-30 e′″ can be bonded together by diffusion bonding.Diffusion bonding techniques that may be appropriate for bonding layers30 a′″-30 e′″ together are described in U.S. Published PatentApplication No. 2010/0171055 A1, published on Jul. 8, 2010, and entitled“Liquid-Chromatography Apparatus Having Diffusion-Bonded TitaniumComponents,” which is hereby incorporated by reference herein as iffully set forth herein. Among other things, U.S. Published PatentApplication No. 2010/0171055 A1 describes a stator assembly for a valvehaving layers diffusion bonded together and having a mounting assemblywith ports therein diffusion bonded to a combination of several layerswhich are themselves diffusion bonded together.

Layers 30 a′″ 30 e′″ need not be made of metal, however, and may insteadcomprise ceramic materials, and in particular may comprise layers whichmay in turn comprise or consist of the same or different ceramicmaterials with some or all of the layers diffusion bonded together orattached using other means. One approach for making stator plate 30′″would be to machine two of the layers, each made of sintered ceramicmaterials, and then bond these two layers together with a green sheetceramic layer. After relatively low temperature sintering, thesandwiched green sheet layer bonds the two other layers together.Alternatively, high temperature co-fired ceramic layers may be used toprovide the stator plate. More detail about techniques for bonding orattaching ceramic layers to one another which may be used for ceramiclayers 30 a′″ 30 e′″ include those described in U.S. Published PatentApplication No. 2009/0321356 A1, which was published on Dec. 31, 2009,and is entitled “Ceramic-Based Chromatography Apparatus and Methods forMaking Same,” which is hereby incorporated by reference as if fully setforth herein. U.S. Published Patent Application No. 2009/0321356 A1describes methods and techniques for using ceramic-based tape, referredto as “green sheet” or “green-sheet tape,” and further describe the useof ceramic materials such as glass, zirconia, and alumina. Those skilledin the art will appreciate that some or all of layers 30 a′″-30 e′″ canbe made of such materials and can be manufactured with the methods anduse of green sheet as described in more detail in U.S. PatentApplication No. 2009/0321356 A1. It will also be appreciated that theforegoing discussion with respect to layers 30 a′″-30 e′″ appliesequally to layers 30 a′-30 d′ for stator plate 30′, and to layers 30a″-30 d″ for stator plate 30″.

FIG. 11 provides an enlarged partial cross-sectional view of analternative embodiment of a mounting device 35 with a guide layer 32 anda stator plate 30. In this particular embodiment, the port of themounting device 35 has a different configuration. Instead of a portdesigned for a flat-bottomed fitting assembly (such as is shown in FIG.6, for example), the port of the mounting device 35 shown in FIG. 11 isconfigured with a conical portion so that the port is adapted tosealingly and removably receive and hold a fitting assembly with agenerally conically-shaped ferrule, a nut, and tubing through the nutand ferrule (not shown).

FIG. 12 provides an isometric view of the stator plate 30, which in theembodiment shown in FIG. 12 has a guide layer 32 and a stator plate 30,as well as the mounting device 35. Shown more clearly in FIG. 12 is agroove 23 which extends longitudinally through each of the guide layer32, the stator plate 30, and the stator ring 25, and along the exterioredge of each. The groove 23 is useful for quick and easy alignment ofthe different components during manufacture and assembly.

FIG. 13 includes an enlarged partial cross-sectional view showing yetanother alternative embodiment. In FIG. 13, the stator plate 30 includesa boss 31 which is adapted to extend upwardly from the top surface ofthe stator plate 30. In addition, the boss 31 is of a selected shape,size, and location so that, when the stator plate 30 and the mountingdevice 35 are attached to one another, the boss 31 extends upwardly fromthe top surface of the stator plate 30 and provides the bottom surfaceof the port of the mounting device 35.

FIG. 14 provides a top view of a stator plate 1401. As shown in FIG. 14,the stator plate 1401 has three holes 1410 a, 1410 b, and 1410 c whichare adapted to receive a threaded screw or other means for attached thestator plate 1401 to a mounting device and/or to a housing of a valvebody (not shown). It will be appreciated that the stator plate 1401 canbe removably attached to the mounting device and/or valve body withthreaded screws. In addition, the stator plate 1401 has an outer annularring 1415, which can have a thicker width than the interior portion 1420of the stator plate 1401. Located near the center of the stator plate1401 are six openings 1425, which are adapted to provided fluid pathwaysand be aligned with openings and/or fluid pathways in a mounting deviceand/or rotor seal (not shown). Also shown in FIG. 14 is a groove ornotch 1405 in the outer edge of the stator plate 1401.

FIG. 15 provides a bottom view of the stator plate 1401. Generally, thesame features in FIGS. 14-18 have the same numbering for ease ofreference. In FIG. 15, openings 1430 can be seen in the bottom side ofthe stator plate 1401.

Referring to FIG. 16, a cross-sectional view of the stator plate 1401taken along line A-A of FIG. 14 is provided. FIG. 16 shows the annularoutside ring 1415 of the stator plate 1401, as well as the interiorportion 1420, openings 1425 and also openings 1430. As can be seen fromFIG. 16, the openings 1425 and 1430 are in fluid communication with oneanother (i.e., each opening 1425 is in fluid communication with anopening 1430 in this view) via fluid pathways 1428.

FIG. 17 is an enlarged partial view of the detail of B from FIG. 14. InFIG. 17, the six openings 1425 are shown more clearly. Those skilled inthe art will appreciate that more or less than six openings 1425 may beprovided by the stator plate 1401.

FIG. 18 provides another cross-sectional view of the stator plate 1401along line C-C of FIG. 16. In addition, FIG. 18 provides an enlargedpartial cross-sectional view of the opening 1425.

Referring now to FIGS. 19-23, additional views and details regarding amounting device 1501 are provided. The same features in FIGS. 19-23 havethe same reference numbers for ease of reference.

In FIG. 19, an isometric view of the mounting device 1501 is provided.Mounting device 1501 has six openings 1525, as well as three openings1510 a, 1510 b, and 1510 c. In addition, the mounting device 1501 has agroove or notch 1515 in its outer edge for easier and quicker alignmentduring assembly, with the groove 1515 running longitudinally along theouter edge of the mounting device 1501. It will be appreciated that thethree openings 1510 a, 1510 b, and 1510 c are each adapted to removablyreceive and hold a threaded screw or other fastener (not shown), so thatthe mounting device 1501 can be removably attached securely to a statorplate and to a valve body (not shown). In addition, it will beappreciated that each of the openings 1525 are adapted to removablyreceive tubing and a fitting assembly therein. In FIG. 19, the openings1525 provide ports into which tubing and fitting assemblies may beinserted and securely connected.

FIG. 20 is a top view of the mounting device 1501. Six openings or ports1525 are shown, as are the three openings 1510 a, 1510 b, and 1510 c forreceiving threaded screws or fasteners. Those skilled in the art willappreciate that more or less than six ports 1525 may be provided, andthat more or less than three openings for screws or other fasteners 1510a, 1510 b, and 1510 c may be provided.

FIG. 21 is a cross-sectional view of the mounting device 1501 takenalong line A-A of FIG. 20. The opening 1510 a for receiving and holdinga threaded screw or fastener is shown. Also shown is an opening 1530 onthe bottom side of the mounting device 1501 to provide the positions forone of the locations pins (not shown). The opening 1530 is adapted toreceive and removably hold the tip of one of the location pins (notshown).

FIG. 22 is a cross-sectional view of the mounting device 1501 takenalong line B-B of FIG. 20. In FIG. 22, two openings or ports 1525 areshown. The port 1525 on the right includes reference numerals toindicate the top portion 1525 a, the middle portion 1525 b, a guideportion 1525 c, and a bottom portion 1525 d of the port 1525 as itextends from the top of the mounting device 1501 to the bottom of themounting device 1501.

FIG. 23 provides a bottom view of the bottom face of the mounting device1501. As shown in FIG. 23, openings 1510 a, 1510 b, and 1510 c extendthrough the mounting device 1501. In addition, openings 1530 areprovided on the bottom face of the mounting device 1501. Finally, thegroove 1515 is also shown in FIG. 23.

Those skilled in the art will appreciate that a replaceable stator plateand a separate mounting device like those described above have severaladvantages over conventional valves. In addition, the mounting device ofthe present disclosure can be reduced in size from conventional statorheads for conventional valves, thus reducing costs of materials and alsoexpensive machining operations to provide the flow passageways inconventional valves (which passageways are no longer needed with thetwo-piece assembly of the present disclosure). In addition, the openingsof the mounting device can be aligned much more closely with theopenings on the first side of the stator plate of the presentdisclosure, thereby reducing the potential for the introduction ofturbulent flow and/or dead volume as is the case for conventionalvalves. At the same time, however, the openings of the stator plate andthe passageways or grooves therein can be precisely controlled, such asto precisely control the volume of such passageways or grooves, whichcan be in the range of about 0.2 to about 0.6 microliters. Moreover, thevalve of the present disclosure can be used even when the fluid flowingthrough the tubing and the valve is at high pressures, includingpressures at anywhere from 5,000 psi to 30,000 psi or higher. Becausethe stator plate can comprise two or more layers which are bondedtogether, each of the layers can comprise one or more portions (such asgrooves or channels) that are designed so that, when the two layers arebonded together, the portions align and fit together to form apassageway through the stator plate formed by the bonded layers. Inaddition, the optional use of the guide layer in the stator plate allowsfor a looser tolerance in terms of the alignment of the openings of thestator plate and the mounting device, thereby reducing cost and alsoproviding a valve in which an operator can more easily and more quicklymake and/or disassemble connections. The stator plate faces, includingthe fluid pathways (whether formed by grooves, passageways, orotherwise), can be coated (such as with a diamond-like carbon) ifdesired to reduce friction and increase hardness.

While the present invention has been shown and described in itspreferred embodiment and in certain specific alternative embodiments,those skilled in the art will recognize from the foregoing discussionthat various changes, modifications, and variations may be made theretowithout departing from the spirit and scope of the invention as setforth in the claims. For example, those skilled in the art willappreciate that the foregoing description and figures generally depict avalve such as a rotary shear valve, but the foregoing disclosure appliesto other types of valves as well. Hence, the embodiment and specificdimensions, materials and the like are merely illustrative and do notlimit the scope of the invention or the claims herein.

We claim:
 1. A removable stator plate for a high-pressure valve for ananalytical instrument, wherein said stator plate comprises: a first sideand an opposing second side, with the first side having a first outsidediameter and a first plurality of openings arranged in a circularpattern proximal to an outside edge of the first side, each of the firstplurality of openings adapted to be removably sealed to a tube having alongitudinal axis perpendicular to the first side and the second side,and the second side having a second outside diameter that is the same asthe first outside diameter and a second plurality of openings arrangedin a circular pattern proximal to a center of the second side whereinthe second side is adapted to sealingly engage with one side of a rotorseal of the high-pressure valve, and wherein the stator plate is adaptedto be removably attached to a body of the high-pressure valve; and aplurality of passageways therethrough wherein each of the passagewaysprovides fluid communication between at least one opening on the firstside and at least one opening on the second side of said stator plate,and wherein said stator plate comprises a plurality of layers bondedtogether.
 2. The stator plate according to claim 1 wherein said statorplate is biocompatible.
 3. The stator plate according to claim 2 whereinsaid stator plate comprises four layers, with at least two layers bondedtogether by diffusion bonding.
 4. The stator plate according to claim 3wherein the first side of said stator plate comprises at least fouropenings and at least two passageways therethrough.
 5. The stator plateaccording to claim 1 wherein said stator plate further comprises one ormore of the following liquid chromatography elements: a sample loop, amixing element, a column, a filter, a heating element, a sensor, or adetector.
 6. The stator plate according to claim 1 wherein said statorplate is adapted to be removed from the high-pressure valve and replacedby a second stator plate, wherein said second stator plate comprises adifferent material than said stator plate.
 7. The stator plate accordingto claim 1 wherein said stator plate is adapted to be removed from thehigh-pressure valve and replaced by a second stator plate, wherein saidsecond stator plate comprises one or more different liquidchromatography elements than said stator plate.
 8. The stator plateaccording to claim 1, wherein the plurality of layers are bondedtogether by diffusion bonding.
 9. A liquid chromatography systemcomprising: a valve comprising: a mounting plate having a first side anda second side, and having a plurality of openings therethrough, whereineach of the plurality of openings is adapted to removably receive tubingin the first side of said mounting plate; and a disc-shaped stator platehaving a first side entirely parallel to a second side, wherein thefirst side of said stator plate is adapted to engage with the secondside of said mounting plate, wherein said stator plate has a pluralityof input openings in the first side arranged proximal to an outside edgeof the first side and a plurality of output openings in the second sideof said stator plate arranged proximal to a center of the second sidewherein said stator plate and said mounting plate are removably attachedto one another, and wherein the stator plate defines a plurality offluid pathways extending between the plurality of input openings and theplurality of output openings.
 10. The liquid chromatography systemaccording to claim 9 wherein said stator plate and said mounting plateare adapted to be removably attached to one another and wherein saidvalve is adapted to operate with fluid pressures of at least 1,000 psi.11. The liquid chromatography system according to claim 10 wherein saidstator plate and said mounting plate are biocompatible.
 12. The liquidchromatography system according to claim 9, wherein the stator platecomprises a plurality of layers bonded together, and wherein theplurality of layers are bonded together by diffusion bonding.
 13. Astator assembly for a high-pressure valve comprising: a mounting platehaving a first side and a second side, and having a plurality ofopenings therethrough, wherein a first side of each of the plurality ofopenings is located in the first side of said mounting plate and isadapted to removably receive tubing therein; and a stator plate having afirst side having a first outside diameter and an opposing second sidehaving a second outside diameter that is the same as the first outsidediameter, wherein the first side is entirely parallel to the secondside, wherein the first side of said stator plate and the second side ofsaid mounting plate are adapted to sealingly engage with one another,wherein said stator plate has a first plurality of openings in the firstside of the stator plate arranged proximal to an outside edge of thefirst side and a second plurality of openings in the second side of saidstator plate arranged proximal to a center of the second side, thestator plate defining a plurality of fluid pathways extending betweenthe first plurality of openings and the second plurality of openings,and wherein said mounting plate and said stator plate are adapted to beremovably attached to one another, and wherein the first side of thestator plate and the openings of the mounting plate are adapted to allowtubing to be removably and sealingly attached to the first side of thestator plate with at least a portion of the tubing extending through theopenings of the mounting plate.
 14. The stator assembly of claim 13wherein the second plurality of openings in the second side of themounting plate and the corresponding first plurality of openings in thefirst side of said stator plate are aligned with one another.
 15. Thestator assembly of claim 14 wherein the first plurality of openings inthe first side of the stator plate define a first diameter, the secondplurality of openings in the second side of the stator plate define asecond diameter, and the second diameter is smaller than the firstdiameter.
 16. The stator assembly of claim 15, wherein the statorassembly is biocompatible.
 17. The stator assembly according to claim 16wherein the stator plate comprises a plurality of layers bondedtogether, and wherein the plurality of layers of said stator plate arebonded together by diffusion bonding.
 18. The stator assembly accordingto claim 13 wherein the first side of said stator plate comprises atleast four openings and at least two passageways therethrough.
 19. Thestator assembly according to claim 13 wherein said stator plate furthercomprises one or more of the following liquid chromatography elements: asample loop, a mixing element, a column, a filter, a heating element, asensor, or a detector.
 20. The stator assembly of claim 13, wherein thestator plate comprises a plurality of layers bonded together, andwherein the plurality of layers are bonded together by diffusionbonding.